3DES Decryption Error Invalid Key Length

Question

I am using 3DESC to decrypt data but i am getting following exception

java.security.InvalidKeyException: Invalid key length: 16 bytes

My Co

Answer 1

DES-EDE cipher can be used with 3 different subkeys therefore the key size should be 24 bytes (3 times 8 bytes). If you want to use only 2 keys (i.e. in this mode first key == last key) then you just have to duplicate the first 8 bytes of the key array.

byte[] key;
if (keyBytes.length == 16) {
    key = new byte[24];
    System.arraycopy(keyBytes, 0, key, 0, 16);
    System.arraycopy(keyBytes, 0, key, 16, 8);
} else {
    key = keyBytes;
}